Certain types of spine disease caused by painful relative motion of vertebrae of the spine warrant a procedure known as spinal fusion. Such abnormal and painful motion can be caused by proximity of discs, abnormal slippage of the vertebrae and other degenerative spinal conditions. In addition, certain conditions involving instability of the spine, and certain types of fractures, infections, deformities or tumors may also warrant spinal fusion.
Traditionally, an open surgical or invasive technique is used, according to which an incision is generally first made; a portion of a bone is removed or decorticated; a bone fusing substance, such as some combination of allograft bone, autograft bone, including bone marrow aspirant, such as marrow from the iliac crest, morselized bone and/or bone morphogenic protein (BMP) or the like is inserted between the decorticated areas of two vertebra, such as the decorticated area of a transverse process of a vertebra and the decorticated area of a transverse process of an adjacent vertebra (performed on both sides of the spine); thereby to fuse the vertebrae. In addition, pedicle screw fixation using screws bilaterally applied to the pedicles of each vertebral segments and rods may also be used while the bone graft solidifies and becomes stable enough to fuse the vertebrae. Also, three or more vertebrae may thus be fused in the spine fusion procedure by extending the bone graft to the transverse processes of three or more vertebrae.
Recently, certain types of minimally invasive spine procedures have become known. Boehm et al., U.S. Pat. No. 6,666,891 teaches an interbody spine fusion method, according to which a disk of the spine is removed, and bone matrix is passed through a dilator to encourage fusion at the disc space. Also, Helm et al., US Patent Application Publication Number 2005/0038514 discloses a spine fusion method and system, according to which the disc is removed and fusion is encouraged at the disc cavity. Also known is an X-tube procedure for interbody spinal, fusion in which a disk is removed, and a sextant is used to attach rods and screws. These references and the X-tube procedure however, involve removal of a disk of the spine and are not directed to performing a non-surgical spinal fusion at a transverse process.
Further, Boehm et al., US Patent Application Publication Number 2005/0203529 describes a minimally invasive method for spinal fusion using a bone graft capsule for facilitating the fusion, such that a portion of the transverse processes of vertebrae is cut and a string of capsules strung on a bioabsorbable string is introduced between the transverse processes by means of a device inserted into the body via a separate incision, which device grasps the string. However, this technique requires multiple incisions in the patient's body and requires cumbersome application of the bone matrix or bone fusion substance. Further, these references do not disclose pushing the bone fusion substance via a delivery tube to the decorticated transverse processes or to other areas of interest.